RR Auction Home
Current Auction Is Open For Bidding
Home |Sitemap|Contact Us| Past Auctions  
 How to Bid   Register to Bid   Auctions   Consign   About Us   Featured Lots   Reviews 
Bidder Login
Show Password

New Bidder Registration
Forgot your password?

The Current Auction
Ends April 22nd
Fine Autograph and Artifacts, Ft. Animation Auction Preview
Begins Apr 23
Advanced Search
By Item Number
Gallery Search
Past Auction Search
How Do I Bid?
What is BidTracker™?
New Bidder Registration
The 30-Minute Rule
Terms and Conditions
New to RR Auction?
About Us
Register to Bid
Jobs at RR Auction
Press Releases
Consign to RR Auction
How to Consign
2021 Auction Calendar
Jan 13
Jan 21
Feb 10
Feb 18
Mar 10
Mar 25
Apr 14
Apr 22
  View All Dates & Deadlines

Item 3030 - Albert Einstein Handwritten Mathematical Manuscript and Typed Letter Signed Catalog 592 (Sep 2020)

Back To Previous Page
(we are no longer accepting bids on this item)
Minimum Bid: $5,000.00
Sold Price: $38,125.00 (includes buyer's premium)


Remarkable pairing of items: a TLS signed "A. Einstein," one page, 8.5 x 11, Institute for Advanced Study, Princeton letterhead, March 4, 1943, responding to Harold Feldman's request to "Prove that ABC is an isosceles triangle if the lines bisecting the angles B and C and going to the opposite sides are equal," in full: "Your little problem has amused me indeed. I was not able to solve it in a purely geometrical way. On the enclosed sheet a proof is given in part algebraically."

On the included sheet, Einstein draws the triangle and marks the angles A, B, and C, the bisecting line m and b, and the bisected halves of the A-C side b´ and b″. He starts out the proof, "mb22 = c2 = b´2 - 2b´c cos α." He goes on to prove the problem presented algebraically, filling the whole sheet with formulas and calculations before concluding: "The fraction being essentially positive it follows c - b = 0." In fine condition. Accompanied by the original mailing envelope and Feldman's original handwritten problem on an index card. Originally sold by Robert F. Batchelder in 1991, and accompanied by a letter to Batchelder from a research assistant associated with the publication of the Collected Papers of Albert Einstein, requesting photocopies of the materials.

Handwritten mathematical manuscripts by Einstein are rare—particularly in so complete a form—and, paired with Einstein's playful letter responding to the challenge, this is a particularly excellent example.

Terms and abbreviations used in our descriptions.


Click image to enlarge Click image to enlarge Click image to enlarge Click image to enlarge

Important Information

Tips For Consignors


For a complete list of auction beginning and ending dates, check our dates and deadlines page.